G40.911
BillableEpilepsy, unspecified, intractable, with status epilepticus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G40.911 an HCC code?
Yes. G40.911 maps to Seizure Disorders and Convulsions under the CMS-HCC V28 risk adjustment model (and Seizure Disorders and Convulsions under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for G40.911
For G40.911 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed G40.911 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G40.911 is the ICD-10-CM diagnosis code for epilepsy, unspecified, intractable, with status epilepticus. Epilepsy of unknown type that is resistant to medication, currently experiencing status epilepticus (prolonged or repeated seizures). G40.911 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering episodic and paroxysmal disorders (g40-g47).
Under the CMS-HCC V28 risk adjustment model, G40.911 maps to Seizure Disorders and Convulsions (HCC 201) with a community, non-dual, aged base RAF weight of 0.262. Under the older V24 model, G40.911 mapped to the same category but with a base RAF weight of 0.244 — V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Intractable epilepsy means the patient has failed adequate trials of at least two antiepileptic drugs. Because G40.911 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G40.911 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Intractable epilepsy means the patient has failed adequate trials of at least two antiepileptic drugs
- •Status epilepticus requires immediate documentation and treatment; this is a medical emergency
Clinical Significance
Unspecified epilepsy, intractable, with status epilepticus captures a critical clinical scenario: drug-resistant seizures of undetermined type in a life-threatening prolonged seizure state. This typically occurs in emergency or inpatient settings where the epilepsy type is unknown but the patient has documented medication resistance and is in active status epilepticus.
Documentation Requirements
- ✓Documentation of intractable epilepsy (failed adequate medication trials)
- ✓Active status epilepticus during the encounter
- ✓Emergency interventions and ICU-level care documentation
- ✓Medications tried and failed
- ✓Plan for determining epilepsy type once acute crisis is managed
- ✓Duration and severity of status epilepticus
Commonly Confused Codes
- •G40.901 — Unspecified epilepsy, NOT intractable, with status epilepticus
- •G40.919 — Unspecified epilepsy, intractable, WITHOUT status epilepticus
- •G40.803 — Other epilepsy, intractable, with status epilepticus; slightly more specific
- •G40.411 — Other generalized epilepsy, intractable, with status epilepticus
- •G40.813 — Lennox-Gastaut, intractable, with status epilepticus; use when syndrome is identified